How Is Wine Made?

We all enjoy a glass of wine, but do you know how it got from the vine to your wine cellar? We take a look at the lengthy processes involved in turning grapes into your favourite beverage!

Before the Harvest

While you may think that the first step in winemaking will be to harvest the grapes, there is a lot of behind-the-scenes work that must take place before the grapes are picked. The goal is to have as many perfectly ripe grapes as possible. To ensure that the optimum grape conditions are produced, vineyard managers will be working around the year to keep the vines pruned. Over the winter months, some of the buds on the plant will be removed, so that the grapes are not overly packed in. If they were, then they would not all gain the full effects of the sun. The same goes for leaves, with some of the leaves being removed to allow more light to hit the growing grapes.

There will then be a ‘green harvest’, in which any bunches of grapes that have yet to ripen will be removed. This will allow the healthier grapes to gain more of the nutrients, enhancing the flavours of these remaining grapes.

The Harvest

Harvesting typically takes place between mid-September and late October; however, the exact time will depend on the wine type. The time of picking is crucial to the characteristics the resulting wine will present, as the level of ripeness will determine the style and character of the wine, as well as the levels of sugar, acidity, and most importantly, alcohol!

The first grapes to be picked will come from the youngest vines, as these are likely to mature the quickest. Grapes used for white wines, such as Sauvignon Blanc, will feature early on the to-pick list. For the most part, grape types will be picked more or less in the colour order, from light to dark wine, for example, Merlot will be picked before Cabernet Sauvignon. Top vineyards will opt to pick the grapes by hand, whereas others may harvest using machines. The bigger vineyards will often employ over 200 people to help during the harvesting season!

Some growers err on the side of caution with grapes, picking them a little before they reach full maturity. This is because leaving grapes until they are over-ripe can prove catastrophic for winemakers. Grapes that are left too long will be overly sweet and alcoholic, losing the fresh fruity taste for that of figs or raisins. Instead, many growers play it safe with early picked grapes. Yet, not quite ripe grapes can also present its own issues. While slightly unripe grapes will present more acidic flavours to play with, there are likely to be fewer tannins in the wine, and less can be done with the skins of each grape.

Crushing

Once the grapes have been harvested, the next step is to de-stem them, removing each individual grape from the stem. Many vineyards will use a machine to aid this process, although there are a number of Chateaux that still complete this stage manually. When each grape is loose, the crushing begins, forming a mixture of grape juice and the skins. This is then transferred to wooden or steel vats where the wine is left to ferment.

Some grapes are fully crushed, whereas other winemakers opt to only slightly break each grape. Alternatively, some wine types leave the full grapes still on the stems to ferment before turning it into wine. Using uncrushed grapes can help to reduce the risk of oxidation while leaving the stems attached can add more tannins to the mix.

Fermentation

Fermentation turns the grape juice into wine, converting sugars present in the fruit juice into alcohol. This process will take around 8-10 days to complete. Typically a stainless steel vat will be used for this process, as this can often be temperature controlled; however, those following a more traditional method will use wood. There are many variations on the fermentation methods between each winemaker, but often the grapes will be kept at between 25 and 30 degrees Celsius during fermentation. The exact temperature will be another factor determining the style of wine produced. A lower temperature will lead to a wine with a fuller body, whereas fermenting at a higher temperature will create a light bodied wine.

Colour

The colour of a wine is gained during the winemaking process through maceration. This is where the skins and seeds of the grapes will be pressed, letting out extra flavours, tannins and colouring, which can then be added to the wine for added body.

Malolactic Fermentation

The wine is then put through a second fermentation, known as the malolactic fermentation. This is much longer than the initial alcoholic fermentation, with the wine being left in a barrel or vat for around two to three months, although vintages may be left for even longer.

Blending

Following the malolactic fermentation, winemakers consider which grape varieties should be blended. When the wine is blended, the different properties of each grape is considered, and a percentage of each grape type grown may be combined to create the perfect wine taste and consistency.

Ageing

After the wine has been blended to perfection, it is back in the barrel! Oak barrels are usually the go-to for ageing purposes, although some places use cement or clay vats to stop the wine from gaining any woody flavours. The time spent in the barrel is when the wine will gain most of its aromas and tastes, such as toastiness or vanilla. Racking will also take place around five times during the ageing process. Racking is when the wine is syphoned from one barrel to another to leave behind and get rid of any sediment formed.

Fining

This is the final step before the wine meets the bottle. The fining process is used to make the wine clearer, by filtering out any remaining proteins and also to remove any excessive bitter flavours. One of the most commonly used products for fining is egg white, although gelatin and casein are also often added. This does, therefore, mean that some wines are not able to be enjoyed by vegans, or even vegetarians in some cases! Vegan wines instead use items such as limestone, plant casein, or different types of clay to complete the fining process. You can find out more about vegan wines here. The fining ingredient is typically added directly into the barrel where it is left for around a month and a half. Racking of the wine will again take place to remove any sediment left by the fining.

Bottling

The final step for winemakers is to bottle up the wine. On average, wine makes it into its bottle around two years after its grapes were first harvested. The chosen bottle is disinfected before the wine is added. Once the bottle is filled, a small layer of gas is then added to the top of the wine, working as a preservative. The bottle is then corked or closed in the chosen method. Labels, however, are not affixed at this time, as each country the wine is exported to will have different labelling requirements! At this final stage, some of the very top wineries will add on some protective extras, such as tags or labels that will prevent counterfeiting, ensuring that you get exactly what you think you’ve paid for!

Were you aware of how much work goes into a bottle of wine? Let us know your thoughts on the winemaking process via our social media channels!